Field of the Invention
The invention relates to a method and a configuration for coding a digitized picture, and to a method and a configuration for decoding a digitized picture.
A block-based picture coding method is described in the ITU-T Draft Recommendation H.263, Video Coding for Low Bitrate Communication, May 1996. In this picture coding method, a picture to be coded has pixels to which coding information is allocated.
In the following text, the term coding information means luminance information (brightness information) or chrominance information (color information).
The pixels are grouped to form picture blocks, which normally contain 8×8 pixels or 16×16 pixels. The picture blocks are grouped to form macroblocks. A macroblock has four picture blocks with luminance information, and two picture blocks with chrominance information.
A so-called hybrid picture coding method is used for coding in the method described in the ITU-T Draft Recommendation H.263, Video Coding for Low Bitrate Communication, May 1996. This means a method in which, firstly, a discrete cosine transformation is carried out for the picture blocks and only spectral coefficients are transmitted while, secondly, attempts are made to avoid transmitting redundant information, contained in successive digitized pictures.
The term redundant information broadly defines coding information which has already been transmitted in a previous picture.
Movement information or shift information is transmitted in this context. This means that a determination is made of how a picture block has moved or shifted in its position within the picture from a previous picture to the picture to be coded. This movement or shift is determined and coded in the form of a vector, the motion vector, for each picture block to be coded. This method is referred to as motion estimation.